U.S. patent application number 16/825043 was filed with the patent office on 2020-11-12 for systems, devices, and methods for coupling a prosthetic implant to a fenestrated body.
The applicant listed for this patent is Aortica Corporation. Invention is credited to Shannon E. EUBANKS, Casey TORRANCE.
Application Number | 20200352700 16/825043 |
Document ID | / |
Family ID | 1000004991464 |
Filed Date | 2020-11-12 |
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United States Patent
Application |
20200352700 |
Kind Code |
A1 |
TORRANCE; Casey ; et
al. |
November 12, 2020 |
SYSTEMS, DEVICES, AND METHODS FOR COUPLING A PROSTHETIC IMPLANT TO
A FENESTRATED BODY
Abstract
Devices, systems, and methods for implanting a patient-specific
prosthesis at a treatment site in a patient are disclosed herein.
In some embodiments, a patient-specific prosthesis includes a
tubular graft and a coupling member. A fenestration can be disposed
in the tubular graft, the fenestration corresponding to a predicted
branch blood vessel location. The coupling member can be disposed
about the fenestration. The coupling member can include a coil
configured to expand from a first configuration to a second
configuration in response to the application of an expanding force.
The coil can be configured to contract to a third configuration
upon removal of the expanding force.
Inventors: |
TORRANCE; Casey; (Snohomish,
WA) ; EUBANKS; Shannon E.; (Woodinville, WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Aortica Corporation |
Bellevue |
WA |
US |
|
|
Family ID: |
1000004991464 |
Appl. No.: |
16/825043 |
Filed: |
March 20, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/US2018/052400 |
Sep 24, 2018 |
|
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16825043 |
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62562776 |
Sep 25, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2210/0014 20130101;
A61F 2/958 20130101; A61F 2250/0039 20130101; A61F 2250/0098
20130101; A61F 2/954 20130101; A61F 2002/061 20130101; A61F 2/07
20130101; A61F 2002/9583 20130101 |
International
Class: |
A61F 2/07 20060101
A61F002/07; A61F 2/954 20060101 A61F002/954; A61F 2/958 20060101
A61F002/958 |
Claims
1. A patient-specific prosthesis for implantation at a treatment
site in a patient, the prosthesis comprising: a tubular graft; a
fenestration disposed in the tubular graft, the fenestration
corresponding to a predicted branch blood vessel location; and a
coupling member disposed about the fenestration, the coupling
member including a coil configured to (a) expand from a first
configuration to a second configuration in response to the
application of an expanding force, and (b) contract to a third
configuration upon removal of the expanding force.
2. The patient-specific prosthesis of claim 1, wherein the coil
includes a radiopaque material.
3. The patient-specific prosthesis of claim 2, wherein the
radiopaque material includes at least one of tungsten, platinum,
gold, and tantalum.
4. The patient-specific prosthesis of claim 1, wherein the coil has
a first diameter in the first configuration, a second diameter in
the second configuration, and a third diameter in the third
configuration.
5. The patient-specific prosthesis of claim 4, wherein the second
diameter is up to three times the first diameter.
6. The patient-specific prosthesis of claim 4, wherein the third
diameter is greater than the first diameter.
7. The patient-specific prosthesis of claim 4, wherein the third
diameter is substantially equal to the first diameter.
8. The patient-specific prosthesis of claim 1, further comprising:
a shape memory core disposed in the coil.
9. The patient-specific prosthesis of claim 1, wherein the coil has
a spring rate of at least about 0.025 N/mm.
10. The patient-specific prosthesis of claim 1, wherein the coil
has a first end and a second end, and the first end is coupled to
the second end to form a ring.
11. A patient-specific prosthesis for implantation at a treatment
site in a patient, the prosthesis comprising: a tubular graft; a
fenestration disposed in the tubular graft, the fenestration
corresponding to a predicted branch blood vessel location; a
coupling member disposed about the fenestration; and a branch stent
configured to be coupled to the fenestration, the branch stent
including an engagement portion for engaging with the coupling
member, and a flexible tail portion extending from the engagement
portion.
12-32. (canceled)
33. A system for treating aneurysms, comprising: a tubular graft; a
fenestration disposed in the tubular graft, the fenestration
corresponding to a predicted branch blood vessel location; a
coupling member disposed about the fenestration, the coupling
member configured to expand from a first configuration to a second
configuration in response to the application of an expanding force,
and contract to a third configuration upon removal of the expanding
force; a radially expandable branch stent configured to be coupled
to the fenestration, the branch stent including an engagement
portion for engaging with the coupling member, and a flexible tail
portion extending from the engagement portion; and an expandable
member configured to transition the radially expandable branch
stent from a collapsed configuration to an expanded configuration,
the expandable member having a first portion configured to expand
the engagement portion of the branch stent, and a second portion
configured to expand the flexible tail portion of the branch stent,
the first portion configured to have a diameter in an expanded
state greater than an inside diameter of the coupling member in the
third configuration.
34-45. (canceled)
46. A method, comprising: disposing a branch stent within a
fenestration of a tubular graft such that an engagement portion of
the branch stent is aligned with a coupling member disposed about
the fenestration, the coupling member being expandable from a first
configuration to a second configuration; radially expanding the
branch stent via an expandable member disposed within the branch
stent such that the engagement portion of the branch stent applies
an expanding force to the coupling member, the expanding force
operable to expand the coupling member from the first configuration
to the second configuration; removing the expanding force and
allowing the coupling member to contract to a third configuration,
the coupling member operable to apply a contracting force to the
branch stent as the branch stent transitions from the second
configuration to the third configuration.
47-49. (canceled)
50. An apparatus, comprising: an expandable member including a
first portion and a second portion, the first portion having a
first wall thickness and the second portion having a second wall
thickness, the first wall thickness being less than the second wall
thickness, the first portion being in fluid communication with the
second portion such that an inflation medium provided to at least
one of the first portion and the second portion causes both the
first portion and the second portion to inflate, the first portion
inflating to a larger diameter than the second portion, the first
portion configured such that, when the first portion is engaged
with a radially expandable stent, an intermediate portion of the
first portion can expand into an opening defined by the radially
expandable stent such that the expandable member is axially secured
relative to the radially expandable stent.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of U.S.
Provisional Patent Application No. 62/562,776, entitled "Systems,
Devices, and Methods for Coupling a Prosthetic Implant to a
Fenestrated Body," filed Sep. 25, 2017, the disclosure of which is
hereby incorporated by reference in its entirety.
BACKGROUND
[0002] The embodiments described herein relate generally to
prosthetic implants and more particularly to devices and methods
for engaging a prosthetic implant, such as, for example, a branch
vessel stent graft, within a fenestration of a second prosthetic
implant, such as, for example, an aortic stent graft.
[0003] Prosthetic devices are often implanted into, for example,
diseased portions of a patient to repair, support, stent, and/or
otherwise facilitate the proper function of those diseased
portions. In some instances, prosthetic devices such as stent
grafts can be used to repair diseased portions of a patient's
vascular system. For example, aneurysms within a patient's vascular
system generally involve the abnormal swelling or dilation of a
blood vessel such as an artery, which typically weakens the wall of
the blood vessel making it susceptible to rupture. An abdominal
aortic aneurysm (AAA) is a common type of aneurysm that poses a
serious health threat. A common way to treat AAA and other types of
aneurysms is to place an endovascular stent graft in the affected
blood vessel such that the stent graft spans across (e.g.,
traverses) and extends beyond the proximal and distal ends of the
diseased portion of the vasculature. The stent graft can, thus,
reline the diseased vasculature, providing an alternate blood
conduit that isolates the aneurysm from the high-pressure flow of
blood, thereby reducing or eliminating the risk of rupture. In
other instances, a prosthetic device can be an implant and/or
mechanism, which can provide structural or functional support to a
diseased and/or defective portion of the body. In some instances,
however, the arrangement of the anatomy can present challenges when
attempting to place and/or secure a prosthetic device (including
stent grafts or the like). Such challenges can result in
misalignment and/or suboptimal configuration of the prosthetic
device within the anatomy.
[0004] Minimally invasive endovascular repair using stent grafts is
often preferred to avoid the risks associated with traditional open
surgical repair. However, these stent grafts can only be used when
the graft can be placed in a stable position without covering major
branch vessels. In the cases of juxtarenal aneurysm where the
dilation extends up to but does not involve the renal arteries, the
proximal portion of the stent graft needs to be secured to the
aortic wall above the renal arteries, thereby blocking the openings
to the renal arteries. Thus, patients with juxtarenal aneurysms,
which represent a significant proportion of abdominal aortic
aneurysm cases, are typically excluded from endovascular
treatment.
[0005] To allow for endovascular repair of a wider range of cases,
surgeons sometimes cut openings in the stent graft body to
accommodate specific branch vessel origins, a process known as
"fenestration". Thus, for example, in treating juxtarenal aneurysms
using a procedure known as Fenestrated Endovascular Aortic Repair
("FEVAR"), the fenestrations or openings of an aortic stent graft
are to be aligned with the branch vessels. Additional stent grafts
(e.g., renal stents) can then be placed in the branch vessels and
secured to the primary stent graft (e.g., aortic stent graft) to
limit movement of the primary stent grafts within the anatomy and
ensure proper blood flow. Additionally, in some cases, an
endovascular stent graft can be placed within one or more specific
branch vessels to further treat an aneurysm and/or to reinforce the
branch vessel in the region of the aneurysm.
SUMMARY
[0006] Devices, systems, and methods for implanting a
patient-specific prosthesis at a treatment site in a patient are
disclosed herein. In some embodiments, a patient-specific
prosthesis includes a tubular graft and a coupling member. A
fenestration can be disposed in the tubular graft, the fenestration
corresponding to a predicted branch blood vessel location. The
coupling member can be disposed about the fenestration. The
coupling member can include a coil configured to expand from a
first configuration to a second configuration in response to the
application of an expanding force. The coil can be configured to
contract to a third configuration upon removal of the expanding
force.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is an illustration of a diseased abdominal aorta
according to an embodiment.
[0008] FIG. 2A is a portion of a stent graft according to an
embodiment and directly after placement within the diseased
abdominal aorta of FIG. 1.
[0009] FIG. 2B is a portion of the stent graft of FIG. 2A and
placed within the diseased abdominal aorta of FIG. 1 and after a
time of indwelling.
[0010] FIG. 3 is an illustration of at least a portion of a
fenestrated stent graft according to an embodiment.
[0011] FIG. 4 is an illustration of the portion of the fenestrated
stent graft of FIG. 3 positioned, for example, within a portion of
a diseased abdominal aorta.
[0012] FIGS. 5A-5D are schematic illustrations of a cross-sectional
view of an assembly in a variety of configurations, according to an
embodiment.
[0013] FIG. 6 is a front view of a coupling member, according to an
embodiment.
[0014] FIG. 7 is a front view of a coupling member, according to an
embodiment.
[0015] FIG. 8A is a perspective view of a coil, according to an
embodiment.
[0016] FIG. 8B is a perspective view of a shape memory core,
according to an embodiment.
[0017] FIG. 9 is an opened and flattened view of a portion of a
branch stent, according to an embodiment.
[0018] FIG. 10A is an opened and flattened view of a portion of a
branch stent, according to an embodiment.
[0019] FIG. 10B is an opened and flattened view of a portion of a
branch stent, according to an embodiment.
[0020] FIG. 10C is an opened and flattened view of a portion of a
branch stent, according to an embodiment.
[0021] FIG. 11 is a side view of an expandable member in an
expanded configuration, according to an embodiment.
[0022] FIG. 12 is a side view of an expandable member in an
expanded configuration, according to an embodiment.
[0023] FIG. 13 is a flow chart illustrating a method of deploying a
branch stent, according to an embodiment.
DETAILED DESCRIPTION
[0024] Devices, systems, and methods for implanting a
patient-specific prosthesis at a treatment site in a patient are
disclosed herein. In some embodiments, a patient-specific
prosthesis includes a tubular graft and a coupling member. A
fenestration can be disposed in the tubular graft, the fenestration
corresponding to a predicted branch blood vessel location. The
coupling member can be disposed about the fenestration. The
coupling member can include a coil configured to expand from a
first configuration to a second configuration in response to the
application of an expanding force. The cod can be configured to
contract to a third configuration upon removal of the expanding
force.
[0025] In some embodiments, a patient-specific prosthesis includes
a tubular graft, a coupling member, and a branch stent. A
fenestration can be disposed in the tubular graft, the fenestration
corresponding to a predicted branch blood vessel location. The
coupling member can be disposed about the fenestration. The branch
stent can be configured to be coupled to the fenestration. The
branch stent can include an engagement portion for engaging with
the coupling member and a flexible tail portion extending from the
engagement portion.
[0026] In some embodiments, a system for treating aneurysms
includes a tubular graft, a coupling member, a radially expandable
branch stent, and an expandable member. A fenestration can be
disposed in the tubular graft, the fenestration corresponding to a
predicted branch blood vessel location. The coupling member can be
disposed about the fenestration, the coupling member configured to
expand from a first configuration to a second configuration in
response to the application of an expanding force, and contract to
a third configuration upon removal of the expanding force. The
radially expandable branch stent can be configured to be coupled to
the fenestration, the branch stent including an engagement portion
for engaging with the coupling member and a flexible tail portion
extending from the engagement portion. The expandable member can be
configured to transition the radially expandable branch stent from
a collapsed configuration to an expanded configuration, the
expandable member having a first portion configured to expand the
engagement portion of the branch stent, and a second portion
configured to expand the flexible tail portion of the branch stent,
the first portion configured to have a diameter in an expanded
state greater than an inside diameter of the coupling member in the
third configuration.
[0027] In some embodiments, a method includes disposing a branch
stent within a fenestration of a tubular graft such that an
engagement portion of the branch stent is aligned with a coupling
member disposed about the fenestration. The coupling member can be
expandable from a first configuration to a second configuration.
The branch stent can be radially expanded via an expandable member
disposed within the branch stent such that the engagement portion
of the branch stent applies an expanding force to the coupling
member. The expanding force can be operable to expand the coupling
member from the first configuration to the second configuration.
The expanding force can be removed and the coupling member can be
allowed to contract to a third configuration. The coupling member
can be operable to apply a contracting force to the branch stent as
the branch stent transitions from the second configuration to the
third configuration.
[0028] In some embodiments, an apparatus includes an expandable
member. The expandable member can include a first portion and a
second portion. The first portion can have a first wall thickness
and the second portion can have a second wall thickness. The first
wall thickness can be less than the second wall thickness. The
first portion can be in fluid communication with the second portion
such that an inflation medium provided to at least one of the first
portion and the second portion causes both the first portion and
the second portion to inflate. The first portion can inflate to a
larger diameter than the second portion. The first portion can be
configured such that, when the first portion is engaged with a
radially expandable stent, an intermediate portion of the first
portion can expand into an opening defined by the radially
expandable stent such that the expandable member is axially secured
relative to the radially expandable stent.
[0029] As used in this specification, the singular forms "a," "an"
and "the" include plural referents unless the context clearly
dictates otherwise. Thus, for example, the term "a member" is
intended to mean a single member or a combination of members, "a
material" is intended to mean one or more materials, or a
combination thereof.
[0030] As used herein, the words "proximal" and "distal" refer to a
direction closer to and away from, respectively, an operator of,
for example, a medical device. Thus, for example, the end of the
medical device contacting the patient's body would be the distal
end of the medical device, while the end opposite the distal end
would be the proximal end of the medical device. Similarly, when a
device such as an endovascular stent graft is disposed within a
portion of the patient, the end of the device closer to the
patient's heart would be the proximal end, while the end opposite
the proximal end would be the distal end. In other words, the
proximal end of such a device can be upstream of the distal end of
the device.
[0031] The embodiments described herein can be formed or
constructed of one or more biocompatible materials. Examples of
suitable biocompatible materials include metals, ceramics, or
polymers. Examples of suitable metals include pharmaceutical grade
stainless steel, gold, titanium, tantalum, tungsten, nickel, iron,
platinum, tin, cobalt, chromium, copper, and/or alloys thereof.
Examples of polymers include nylons, polyesters, polycarbonates,
polyacrylates, polymers of ethylene-vinyl acetates and other acyl
substituted cellulose acetates, non-degradable polyurethanes,
polystyrenes, polyvinyl chloride, polyvinyl fluoride, poly(vinyl
imidazole), chlorosulphonate polyolefins, polyethylene oxide,
polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE),
urethanes, and/or blends and copolymers thereof.
[0032] The embodiments and methods described herein can be used to
form a patient-specific prosthetic device and/or to facilitate the
function and/or the integration of the prosthetic device within a
portion of a patient. For example, in some embodiments, the devices
and/or methods described herein can be used in conjunction with
and/or can otherwise be included in endovascular repair using stent
grafts. Although the embodiments are shown and described herein as
being used, for example, to facilitate endovascular repair, in
other embodiments, any of the devices and/or methods described
herein can be used to facilitate treatment of any portion of a
patient. For example, the devices and methods described herein can
form and/or can facilitate the integration of any suitable implant,
prosthesis, device, mechanism, machine, and/or the like within a
portion of the body of a patient such as the patient's vascular
system, nervous system, muscular-skeletal system, etc. Therefore,
while some embodiments are shown and described herein as being used
in the endovascular repair of an abdominal aortic aneurysm, they
are presented by way of example and are not limited thereto.
[0033] Some of the devices and/or methods described herein can be
used in minimally invasive treatment techniques such as
endovascular repair using stent grafts. Such repair techniques are
generally preferred over traditional open surgical repair and often
result in reduced morbidity or mortality rates. In some instances,
however, the arrangement of the diseased vasculature can result in
a need to alter a portion of the stent graft prior to insertion
into the body. For example, in an endovascular repair of an
abdominal aortic aneurysm, the aneurysm can be situated adjacent to
and/or directly distal to normally functioning vessels branching
from a portion of the aorta. In order to reline the aneurysm with
the stem graft, surgeons or manufacturers often cut openings in the
stent graft fabric to accommodate specific branch vessel origins, a
process known as "fenestration." Specifically, in treating
juxtarenal aneurysms and/or when treating other aneurysms, shown in
illustration in FIG. 1 for instance, the fenestrations or openings
of the stent grafts can correspond to a size, shape, and/or
relative position of, inter alia, the renal arteries, the superior
mesenteric artery (SMA), and/or the celiac artery (not shown in the
illustration in FIG. 1).
[0034] Traditionally, the fenestration process involves
measurements based on medical images (such as CT scans) of the
vessel origins. For example, in some instances, longitudinal
distances of branch vessels can be measured and relative angular
locations of the branch vessels can be estimated and/or calculated
from a reference point. Based on these measurements and/or
calculations, a surgeon or manufacturer can mark and cut the stent
fabric of a stent graft to define one or more fenestrations. The
fenestrated stent graft can then be positioned within the diseased
vasculature (e.g., via an endovascular procedure) and oriented to
substantially align the fenestrations with openings of the
corresponding branch vessels.
[0035] In some instances, fenestrations in the fenestrated bodies
(e.g., fenestrated stent grafts or vessel walls) described herein
can be generated and/or otherwise formed based on medical imaging
data of a diseased portion of a patient's vascular system (e.g., an
abdominal aortic aneurysm). For example, an electronic device such
as a personal computer, workstation, laptop, etc, can receive the
imaging data and can calculate and/or otherwise define a digital
representation of the imaging data. Based on the digital
representation, the electronic device can define one or more
templates, process plans, instructions, data sets, and/or the like
associated with and/or indicative of a desired set of fenestration
locations along a body (e.g., a stent graft). In some instances,
the electronic device can output a map, plan, and/or template,
which in turn, can be used by a doctor, surgeon, technician, and/or
manufacturer to form a fenestrated body (e.g. a fenestrated stent
graft). For example, in some embodiments, such a template or the
like can be substantially similar to those described in U.S. Patent
Publication No. 2013/0296998 entitled, "Fenestration Template for
Endovascular Repair of Aortic Aneurysms," filed May 1, 2013 ("the
'998 publication") and/or those described in U.S. patent
application Ser. No. 15/163,255 entitled, "Devices and Methods for
Anatomic Mapping for Prosthetic Implants," filed May 24, 2016 ("the
'255 application"), the disclosures of which are incorporated
herein by reference in their entireties.
[0036] In other instances, fenestrations in the fenestrated bodies
(e.g. a fenestrated stent grafts or vessel walls) can be formed
without such templates. For example, in some embodiments, the
electronic device can output instructions and/or code (e.g.,
machine code such as G-code or the like) to a computerized
numerical control (CNC) device and/or a computer-aided
manufacturing (CAM) device, which in turn, can perform one or more
manufacturing processes or the like associated with forming and/or
otherwise marking fenestration locations along a patient-specific
prosthesis (e.g., a stent graft). The formation of a
patient-specific prosthesis can be performed in a manual process or
in at least a partially, automated process. Moreover, a change in
the arrangement of a portion of the anatomy resulting from the
insertion and/or indwelling of the prosthesis can be determined
and/or calculated using the devices and/or methods described in
International Patent Application No. PCT/US2016/041355, entitled
"Devices and Methods for Anatomic Mapping for Prosthetic Implants,"
filed Jul. 7, 2016 ("the '355 application"), the disclosure of
which is incorporated herein by reference in its entirety.
[0037] FIGS. 1-29 illustrate a diseased portion of a patient's
abdominal aorta 10. While portions of the abdominal aorta 10 are
described below, the discussion of the abdominal aorta 10 is not
exhaustive; rather, the discussion below provides a reference to
the relevant anatomic structures. Moreover, the discussion of the
anatomic structures e.g., of the abdominal aorta 10) refers to the
position, orientation, etc. of such structures relative to the
patient rather than as viewed by an observer (e.g., a doctor). For
example, when referring to a "left" side of a patient or to
anatomic structures disposed on or near the "left" side of the
patient, "left" is intended to describe a position relative to the
patient and/or from the patient's perspective, as viewed in an
anterior direction (e.g., forward).
[0038] The abdominal aorta 10 (also referred to herein as "aorta")
has a proximal end portion 11, receiving a flow of blood from the
descending aorta (not shown), and a distal end portion 12,
supplying a flow of blood to the lower limbs. As shown in FIG. 1,
the aorta 10 at or near the proximal end portion 11 supplies a flow
of blood to the right renal artery 13 and the left renal artery 14,
which in turn, supply blood to the right and left kidney (not
shown), respectively. Although not shown in FIG. 1, the proximal
end portion 11 of the aorta 10 also supplies a flow of blood to the
superior mesenteric artery (SMA) and the celiac artery. The distal
end portion 12 of the aorta 10 forms the iliac bifurcation 20,
through which the aorta 10 supplies a flow of blood to the right
common iliac artery 15 and the left common iliac artery 16, which
in turn, supply blood to the right and left lower limbs,
respectively. As shown in FIG. 1, this patient has an abdominal
aortic aneurysm (AAA) 17 positioned distal to the renal arties 13
and 14 and proximal to the iliac bifurcation 20. More specifically,
the AAA 17 is disposed in a position that precludes the attachment
of a proximal end portion of a stent graft between the renal
arteries 13 and 14 and the AAA 17, and thus, a fenestrated stent
graft 160 (see e.g., FIGS. 2A and 2B) is used for endovascular
repair of the AAA 17.
[0039] In some instances, endovascular repair of the AAA 17
includes scanning and/or otherwise capturing anatomic imaging data
associated with the patient's aorta 10. For example, an imaging
device can be an X-ray device, a computed tomography (CT) device, a
computed axial tomography (CAT) device, a magnetic resonance
imaging device (MRI), a magnetic resonance angiogram (MRA) device,
a positron emission tomography (PET) device, a single photon
emission computed tomography (SPECT) device, an ultrasound device,
and/or any other suitable device for imaging a portion of the
patient and/or a combination thereof (e.g., a CT/MRA device, a
PET/CT device, a SPECT/CT device, etc. The imaging data captured by
the imaging device can thus, be used to determine salient features
of the patient's aorta 10 such as, for example, the branch vessels
in fluid communication with the aorta 10. For example, a doctor,
surgeon, technician, manufacturer, etc. can use the imaging data to
determine and/or calculate a size, shape, position, and/or
orientation of the aorta 10, the branch vasculature in fluid
communication with the aorta 10 (e.g., the renal arteries 13 and
14), and/or any other suitable vasculature or anatomic structure.
In some instances, the doctor, surgeon, technician, manufacturer,
etc. can form and/or define one or more fenestrations 165 in the
stent graft 160 associated with the determined and/or calculated
characteristics of at least the renal arteries 13 and 14, as
described in the '998 application, the '255 application, and/or the
'355 application, incorporated by reference above.
[0040] As shown in FIG. 2A, the stent graft 160 can be positioned
within a portion of the patient's abdominal aorta 10 via an
endovascular procedure. For example, the stent graft 160 can be
disposed within a delivery catheter (e.g., in a collapsed,
compressed, restrained, and/or otherwise un-deployed
configuration), which is inserted into, for example, the femoral
artery (not shown). The delivery catheter can be advanced through
the artery and into the abdominal aorta 10. Once advanced to a
desired position within the abdominal aorta 10, the delivery
catheter can be withdrawn relative to the stent graft 160. As the
delivery catheter is retracted and/or withdrawn, the stent graft
160 transitions from the collapsed configuration to an expanded or
deployed configuration, thereby stenting a portion of the abdominal
aorta 10.
[0041] The stent graft 160 includes a proximal end portion 161 and
a distal end portion 162 and defines a lumen therethrough 163. The
stent graft 160 can be any suitable stent graft. For example, the
stent graft 160 can be formed from a resilient, biocompatible
material such as those described above. For example, a stent graft
can include a stent or framework to which a graft material is
coupled. In some embodiments, the stent (i.e., framework) can be
constructed from a metal or metal alloy such as, for example,
nickel titanium (nitinol) and the graft material can be constructed
from a woven polymer or fabric such as, for example,
polytetrafluoroethylene (PTFE) or polyethylene terephthalate (PET
or Dacron.RTM.). In some embodiments, the graft material or fabric
can be woven onto the stent and/or coupled to the stent in any
other suitable manner to form the stent graft (e.g., the stent
graft 160).
[0042] The stent graft 160 also includes a set of stiffening
members 164 disposed circumferentially about the stent graft 160.
The stiffening members 164 can be any suitable structure that can,
for example, bias the stent graft 160 in an open configuration,
thereby structurally supporting the stent graft material (also
known as "stent fabric" or "graft fabric"). In some embodiments,
the stiffening members 164 can be formed from a metal or a metal
alloy such as, for example, those described above. In some
embodiments, such a metal or metal alloy, for example, is
radiopaque and/or otherwise coated with a radiopaque material
configured to be visible using, for example, fluoroscopy. The
stiffening members 164 can transition from a restrained or deformed
delivery configuration (e.g., when disposed in a delivery catheter)
to an expanded and/or biased indwelling configuration, as shown in
FIG. 2A.
[0043] In this embodiment, the stent graft 160 defines the set of
fenestrations 165, as described above. As described herein, the
position of the fenestrations 165 along the stent graft 160 can be
based on anatomic imaging data and/or one or more digital
representations of the patient's anatomy. A doctor, surgeon,
technician, and/or manufacturer can then use the imaging data
and/or digital representations to define the fenestrations 165 in
the graft fabric. As shown, in this example, the fenestrations 165
are each aligned with its corresponding renal artery 13 or 14 and
can each have a size, shape, and/or configuration that is
associated with its corresponding renal artery 13 or 14. In this
manner, the fenestrations 165 can allow blood to flow from the
aorta 10 and into the right renal artery 13 and the left renal
artery 14 via the fenestrations 165. Although not shown in FIG. 2A,
the stent graft 160 can define one or more fenestrations associated
with other branch vessels stemming from the aorta 10 such as, for
example, the superior mesenteric artery (SMA), the celiac artery,
and/or the like.
[0044] As shown in FIG. 2B, the placement and/or indwelling of the
stent graft 160 within the aorta 10 can, for example, alter, shift,
rotate, translate, morph, and/or otherwise reconfigure the
arrangement of the patient's aorta 10. As a result, the openings of
the renal arteries 13 and 14 are shifted relative to the
fenestrations 165 defined by the stent graft 160. In some
instances, the shifting of the aorta 10 relative to the stent graft
160 results in at least a partial blockage of the renal arteries 13
and 14, as shown in FIG. 2B. For example, in some instances, the
openings of the renal arteries 13 and 14 can be about 4 millimeters
(mm) to about 7 mm, and the shifting and/or rearrangement of the
aorta 10 can result in a shifting of the openings of the renal
arteries 13 and 14 relative to the fenestrations 165 by about 1 mm,
about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7
mm, or more (or fraction of a Millimeter there between). Thus,
despite defining the fenestrations 165 in desired positions along
the stent graft 160 based on the imaging data, the shifting of the
aorta 10 resulting from the placement and/or indwelling of the
stent graft 160 can result in a blockage of the renal arteries 13
and 14. In some instances, the shifting of the aorta 10 can result
in about a 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or
100% (or any percent or fraction of a percent there between)
blockage of the renal arteries 13 and 14. Although not shown in
FIGS. 2A and 2B, the shifting of the aorta 10 can result in a
similar misalignment of any branch vessel relative to its
corresponding fenestration in the stent graft 160. In some
embodiments, an electronic device can be configured to determine
and/or calculate the shift in the anatomy that would result from
the insertion and/or indwelling of prosthesis (e.g., a stent graft)
and can define one or more digital representations of the shifted
anatomy. One or more fenestrations can be formed in a stent graft
(e.g., the stent graft 160) based on the calculated shift, as
described in the '998 application, the '255 application, and/or the
'355 application, incorporated by reference above.
[0045] FIG. 3 illustrates at least a portion of a fenestrated stent
graft 260 according to an embodiment. As described above, a stent
graft can define one or more fenestrations configured to
accommodate one or more branch vessels when the stent graft is
deployed in an aorta. Specifically, in this embodiment, the
fenestrated stent graft 260 includes a proximal end portion 261 and
a distal end portion 262, and defines a lumen 263 and a set of
fenestrations 265. The fenestrated stent graft 260 can be any
suitable stent graft and/or prosthesis. For example, in some
embodiments, the fenestrated stent graft 260 can be an
off-the-shelf stent graft. In other embodiments, the fenestrated
stent graft 260 can be a patient-specific stent graft with a size,
shape, and/or configuration corresponding to the patient's
anatomy.
[0046] The fenestrated stent graft 260 (also referred to herein as
"stent graft") can have any suitable shape, size, and/or
configuration. For example, in some embodiments, the stent graft
260 can have a size that is associated with a size of the lumen
defined by the aorta. In other embodiments, the fenestrated stent
graft 260 can have a size that is associated with an adjusted or
calculated size of the lumen defined by the aorta resulting from
the endovascular placement of the stent graft 260. Moreover, the
stent graft 260 can have any suitable mechanical properties such
as, for example, strength, stiffness, etc.
[0047] As shown in FIG. 3, in some embodiments, the stent graft 260
can include stent 264 and a graft fabric 266. The stent 264 can be,
for example, any suitable stent and/or framework configured to
increase a stiffness of the stent graft 260 and/or to provide
structural support for the stent graft 260. As described above, the
stent 264 can be formed from any suitable metal or metal alloy such
as Nitinol. In some embodiments, the stent 264 can be configured to
transition between a first, expanded and/or implanted configuration
and a second, collapsed, and/or delivery configuration.
Furthermore, in some instances, the stent 264 can be biased such
that the stent 264 is in the first configuration until a force is
exerted on the stent 264 to transition it from the first
configuration to the second configuration (e.g., when disposed in a
delivery cannula or the like).
[0048] The graft fabric 266 can be formed from any suitable polymer
or fabric such as, for example, Dacron.RTM. or the like. In some
embodiments, the graft fabric 266 can be woven around and/or
through the stent 264. In other embodiments, the graft fabric 266
can be coupled to the stent 264 via sutures, a friction fit, or an
adhesive, and/or can encapsulate the stent 264 between at least two
layers of graft fabric 266. As shown in FIG. 3, the graft fabric
266 defines the fenestrations 265, which can be arranged relative
to the stent 264 such that the fenestrations 265 do not overlap the
stent 264. In other words, the fenestrations 265 can be arranged
along the stent graft 260 such that one or more portions of the
stent 264 do not span and/or otherwise traverse the fenestrations
265. In other embodiments, one or more portions of the stent 264
can span and/or otherwise traverse the fenestration 265. Moreover,
as described in detail above, the fenestrations 265 can be defined
by the graft fabric 266 at locations along the stent graft 260
based on an updated, projected, anticipated, and/or otherwise
calculated digital representation of a portion of a patient's
vasculature.
[0049] As described above, the stent graft 260 can be any suitable
stent graft and can be formed via any suitable manufacturing
process or processes. In some embodiments, the stent graft 260 can
be manufactured as an off-the-shelf stent graft and the
fenestrations 265 can be formed in the graft material 266 in a
subsequent manufacturing process. In other embodiments, the stent
graft 260 can be manufactured as a "custom" or not-off-the-shelf
stent graft. While specific methods of manufacturing are described
herein, it is to be understood that the methods are presented by
way of example only and not limitation. Moreover, the methods of
manufacturing described herein can be performed at a single
facility and/or in a single manufacturing process or can be
performed at multiple facilities and/or in multiple manufacturing
processes. In some instances, portions of the methods of
manufacturing described herein can be performed by an end user such
as a doctor, surgeon, technician, nurse, etc. Thus, while the
manufacturing of the stent graft 260 is specifically described
below, the stent graft 260 can be formed via any suitable
manufacturing process or processes and is not limited to those
discussed herein.
[0050] In some instances, the stent graft 260 can be manufactured
with a general shape, diameter, length, etc. associated with a
patient's aorta based on, for example, calculations from anatomic
imaging data of the patient. In other embodiments, the stent graft
260 can have a general shape, size, and/or configuration associated
with the updated model defined by the electronic device, which in
turn, corresponds to a calculated, projected, and/or modified
arrangement of the aorta in response to the insertion and
indwelling of, for example, the stent graft 260, as described in
detail above. Hence, a stent graft 260 generally has a tubular or
cylindrical shape. In some embodiments, the diameter of the lumen
263 is at least partially based on a diameter of the calculated,
projected, and/or modified lumen defined by the aorta. Moreover,
the stent graft 260 can have a stiffness and/or any other suitable
mechanical properties associated with an anticipated amount and/or
method of shifting of the aorta resulting from the insertion and/or
indwelling of the stent graft 260, as described in the '998
application, the '255 application, and/or the '355 application,
incorporated by reference above.
[0051] The fenestrations 265 can be defined along the stent graft
260 such that each fenestration 265 corresponds to a calculated
position of the corresponding branch vasculature such as, for
example, the renal arteries, and each fenestration 265 can be
formed in any suitable manner, as described in the '998
application, the '255 application, and/or the '355 application,
incorporated by reference above.
[0052] As shown in FIG. 4, when the fenestrations 265 are defined
along the stent graft 260, the stent graft 260 can be positioned
within a portion of the patient's body using any suitable
endovascular procedure. In this embodiment, the stent graft 260 is
positioned within the patient's aorta 10. As shown, the stent graft
260 can include, for example, a first set of fenestrations 265A,
which are associated with and/or otherwise correspond to the right
renal artery 13 and the left renal artery 14. Specifically, each of
the fenestrations 265A are aligned with its corresponding renal
artery 13 or 14 and can each have a size, shape, and/or
configuration that is associated with its corresponding renal
artery 13 or 14. In some embodiments, the size, shape, and/or
position of the fenestrations 265A is associated with and/or
substantially corresponds to the adjusted and/or calculated size,
shape, and/or position of its corresponding renal artery 13 and 14.
For example, placing the stent graft 260 within aorta 10 can, for
example, alter, shift, rotate, translate, morph, and/or otherwise
reconfigure the arrangement of the patient's aorta 10. Thus, by
basing the stent graft 260 off of the updated model, the size,
shape, and/or position of the fenestrations 265 defined by the
stent graft 260 can correspond to the desired branch vasculature
(e.g., the right renal artery 13 and/or the left renal artery 14).
Moreover, in addition to positioning the stent graft 260 within a
portion of the patient's aorta 10, the renal arteries 13 and/or 14
can also be stented, for example, through the fenestrations 265A
(not shown in FIG. 4). Stenting of the renal arteries can be
carried out with secondary branch stents (not shown in FIG. 4) that
engage with the fenestrated body of the stent graft 260 at the
fenestrations 265A and extend within branch arteries like the renal
arteries 13 and/or 14. As such, the fenestrations 265A on the stent
graft 260 and the secondary branch stents (not shown) positioned to
correspond to the branch arteries can help with the axial and/or
radial alignment and positioning of the stem graft 260 during
deployment. Further the fenestrations 265A and the secondary branch
stents (not shown) can also help maintain the alignment and
positioning of the stent graft 260 relative to the patient's aorta
10 after placement.
[0053] As shown in FIGS. 3 and 4, in some embodiments, the stent
graft 260 can include a second set of fenestrations 2658, which are
associated with and/or otherwise correspond to other branch vessels
that otherwise, might be blocked by an un-fenestrated portion of
the stent graft 260. For example, the fenestrations 265B can be
associated with and/or otherwise correspond to the superior
mesenteric artery (SMA) 18 and the celiac artery 19, respectively.
In other embodiments, the stent graft 260 can define fenestrations
to accommodate more or fewer branch vessels than illustrated here.
For example, in some embodiments, the stent graft 260 can define
fenestrations to accommodate the inferior mesenteric artery (IMA),
internal iliac arteries, and/or the like. Thus, the fenestrations
265 defined by the stent graft 260 can allow blood to flow from the
aorta 10 to the branch vasculature, which would otherwise be
obstructed by the stent graft 260 material.
[0054] In some embodiments, the arrangement of the stent graft 260
and/or the patient's aorta can be such that a fenestration 265 is
partially defined by the stent graft 260. For example, as shown,
the proximal most fenestration 265B is disposed at the proximal end
of the stent graft 260 and corresponds to the celiac artery 19 that
is partially covered by the graft material during deployment. As
such, the fenestration 265B for the celiac artery 19 is partially
circular or U-shaped to accommodate the portion of the celiac
artery 19 otherwise blocked by the graft material. In other
embodiments, any of the fenestrations 265 can have non-circular
and/or irregular shapes.
[0055] In some embodiments, the fenestrations 265 can be marked to
facilitate location of the fenestrations 265 during deployment of
the stent graft 260 and to facilitate the coupling of branch stents
(not shown) with the stent graft 260. For example, the peripheral
edges 267A or 267B of the stent graft 260 that define the
fenestrations 265A or 265B may be sutured using gold wires and/or
wires of other radiopaque materials. Similarly, the location of the
fenestration 265 can be marked by one or more radiopaque markers.
Such radiopaque wires or markers can facilitate fluoroscopic
visualization of the fenestrations 265 during an endovascular
repair procedure and allow a physician to locate the fenestration
265 with respect to the corresponding branch vessel. In other
embodiments, the fenestrations 265 can be sutured and/or otherwise
marked using any suitable material that can increase visibility,
for example, when using any suitable imaging device (e.g., MRI
scan, CAT scan, PET scan, X-Ray scan, ultrasound, etc.). Such
markers can be placed and/or sutured in any suitable manufacturing
process, which can be combined with or separate from the formation
of the fenestrations 265.
[0056] As described above, in some embodiments, a secondary branch
stent can be coupled within a fenestration (e.g., fenestrations
265) of a stent graft (e.g., stent graft 260). The relative
position of the secondary branch stent can help in the axial and
radial alignment and/or positioning of the stent graft 260 with
respect to the patients aorta 10 during deployment. During
placement of the stent graft the secondary stent can be disposed
within a branch vessel (e.g., the SMA 18) extending from a
patient's aorta such that the secondary stent can aid in
reinforcing the branch vessel in an open position. Additionally,
the secondary stent may help maintain the axial and/or radial
positioning of the stent graft relative to the patient's aorta
(e.g., aorta 10) after placement. The secondary stent may be
movable within and/or relative to the fenestration such that a
motion of the branch vessel can be accommodated (i.e., vessel
tortuosity can be compensated for and vessel kinking can be
prevented). In some embodiments, a fenestrated body, such as a main
stent graft, can include a flexible portion surrounding a
fenestration such that a rigid branch stent engaged with the
fenestrated body at the fenestration can rotate within the
fenestration. For example, FIG. 5A is a schematic illustration of a
cross-sectional view of an assembly 300. The assembly 300 includes
a fenestrated body 360, a branch stent graft 330 (also referred to
herein as a "branch stent"), a radially expandable coupling member
320, and an expandable member 340. The fenestrated body 360 can be,
for example, a tubular graft and/or a main stent graft, such as an
aortic stent graft. The fenestrated body 360 can have the same or
similar structure and/or function as any of the other fenestrated
bodies or stent grafts described herein, such as, for example,
stent graft 160 or stent graft 260. The fenestrated body 360 can
define a fenestration 365 and include an engagement portion 368
surrounding the fenestration 365. The fenestration 365 can
correspond to a predicted branch blood vessel location.
[0057] The coupling member 320 can be coupled to the fenestrated
body 360 such that the coupling member 320 is disposed about the
fenestration 365. For example, the coupling member 320 can
partially or completely surround the fenestration 365. The coupling
member 320 can include, for example, a coil (not shown). The coil
can include a radiopaque material such that the coil can be viewed
using radiographic imaging. The radiopaque material can include
tungsten, platinum, gold, tantalum, and/or any other suitable
radiopaque material. In some embodiments, the coil can have a
spring rate of at least about 0.025 N/mm. In some embodiments, the
cod can have a first end and a second end, and the first end can be
coupled to the second end (e.g., via welding) to form a ring.
[0058] The coupling member 320 can be coupled to the fenestrated
body 360 via any suitable coupling mechanism. For example, the
coupling member 320 can be stitched to the fenestrated body 360
using, for example, sutures. In some embodiments, the coupling
member 320 can be coupled to the fenestrated body 360 via
polyurethane. In some embodiments, the coupling member 320 can be
coupled to the fenestrated body 360 via a mechanical coupling, via
welding, or via any apparatus or method described in International
Application No. PCT/US2017/037157, filed Jun. 13, 2017, entitled
"Systems, Devices, and Methods for Marking and/or Reinforcing
Fenestrations in Prosthetic Implants" (referred to herein as the
'157 application), which is hereby incorporated by reference in its
entirety.
[0059] The coupling member 320 can be configured to expand from a
first configuration having a first diameter (e.g., D1) to a second
configuration having a second diameter (e.g., D2 shown in FIG. 5B)
in response to the application of an expanding force, such as an
expanding force applied by the expandable member 340. After
expanding, the coupling member 320 can be configured to contract
from the second configuration to a third configuration having a
third diameter (e.g., D3 shown in FIG. 5C) upon removal of the
expanding force. Additionally, the coupling member 320 can be
configured to engage with the branch stent graft 330. For example,
the expandable member 340 can be expanded such that the expandable
member 340 applies an expanding force to an inner wall of the
branch stent graft 330, causing an outer wall of the branch stent
graft 330 to contact, engage with, and/or expand the coupling
member 320 from the first configuration to the second
configuration, as described in more detail below with reference to
FIGS. 5A-5D.
[0060] In some embodiments, the coupling member 320 can optionally
include a shape memory core (not shown) disposed in the coil (e.g.,
within a central lumen of the coil). The shape memory core can
include a shape memory material or structure such that the shape
memory core can revert to a predetermined shape (e.g., a circular
shape). For example, the coupling member 320 can include a shape
memory material such that the coupling member 320 can revert to a
circular shape after being collapsed or compressed for delivery to
a particular vascular location via a delivery sheath. The shape
memory core can also prevent kinking of the coil during the
collapsing, delivery, and expansion of the coil at the desired
vascular location. In some embodiments, the shape memory core can
include a shape memory alloy, such as, for example, Nitinol (i.e.,
nickel titanium). In some embodiments, the shape memory core can be
shaped such that it forms an incomplete or broken ring (i.e., not a
complete or closed ring). In some embodiments, the shape memory
core can be shaped as a split key ring. Thus, when the coupling
member 320 expands, the shape memory core can also expand and the
ends of the shape memory core within the coupling member 320 can
separate. When the coupling member 320 contracts to a smaller
diameter, the shape memory core can also contract and the ends of
the shape memory core can approach each other. In some embodiments,
the coil in combination with the shape memory core can have a
spring rate of at least about 0.025 N/mm. In some embodiments, the
coil alone (i.e., without the shape memory core) can have a spring
rate of at least about 0.025 N/mm.
[0061] The branch stent 330 can be expandable from an initial,
contracted configuration (shown in FIG. 5A) to an expanded
configuration (shown in FIG. 5B). The branch stent 330 or a portion
of the branch stent (e.g., an engagement portion 332 described
below) can also be able to be contracted from the expanded
configuration to a final, contracted configuration (shown in FIG.
5C). As identified in FIG. 5B and described in more detail with
reference to branch stent 730 shown in FIG. 9, the branch stent 330
can include an engagement portion 332 and a flexible tail portion
334 extending from the engagement portion 332. In some embodiments,
the engagement portion 332 can be more rigid than the flexible tail
portion 334. In some embodiments, the flexible tail portion 334 can
be about 20% more flexible than the engagement portion 332. In some
embodiments, the branch stent 330 can include a transition portion
(not shown) disposed between the engagement portion 332 and the
flexible tail portion 334 and coupling the engagement portion 332
to the flexible tail portion 334. The engagement portion 332 can
include a proximal portion 331, an intermediate portion 335, and a
distal portion 333. When the branch stent 330 is in the expanded
configuration, a diameter of the intermediate portion 335 can be
less than the diameter of the proximal portion 331 and the diameter
of the distal portion 333 such that the engagement portion 332 of
the branch stent 330 has, for example, a saddle or hourglass shape.
In some embodiments, the flexible tail portion 334 can be any
suitable diameter in a deployed configuration (e.g., as shown in
FIG. 5D) relative to a diameter of the engagement portion 332
(e.g., the diameter of the intermediate portion 335) or a diameter
of the coupling portion 320.
[0062] In some embodiments, the branch stent 330 or a portion of
the branch stent 330 can have a lower radial strength than the
radial strength of the coupling member 320. For example, in some
embodiments, the radial strength of the target zone or intermediate
portion 335 of the engagement portion can be less than the radial
strength or resistance to expansion of the coupling member 320.
Thus, as the branch stent 330 is expanded, the intermediate portion
335 can be prevented from expanding to as great of a diameter as
the proximal portion 331 or the distal portion 333 by the coupling
member 320. Similarly, due to the contracting force of the coupling
member 320 being greater than the radial force applied by the
target zone or intermediate portion 335 of the branch stent 330
against the coupling member 320, the contracting force of the
coupling member 320 can be sufficient to compress the target zone
after the expanding member 340 has been removed.
[0063] In some embodiments, the proximal portion 331 can include a
band or ring of closed cells. The band or ring of closed cells can
be positioned proximal the fenestration 365. One, some, or all of
the closed cells in the band can have a diamond shape. The band or
ring of closed cells can be configured and positioned to provide
increased radial strength to the proximal end of the branch stent
330 to prevent the branch stent 330 from collapsing (e.g., due to
the force applied by the coupling member 320 during expansion of
the branch stent 330). For example, in some embodiments, the band
or ring can have increased radial strength and be more resilient to
compression than a weakened or target portion of the branch stem
330. The band or ring of closed cells can also prevent the
expandable member 340 from moving proximally relative to the branch
stent 330 (e.g., during the expansion of the expandable member
340).
[0064] In some embodiments, the engagement portion 332 can include
a target zone configured to interface with the coupling member 320.
In some embodiments, the target zone can include the intermediate
portion 335. In some embodiments, the target zone can include the
intermediate portion 335 and a portion of one or both of the
proximal portion 331 and the distal portion 333. The target zone
can have any suitable length. For example, the target zone can have
a length in the range of about 2 mm to about 12 mm, about 2 mm to
about 8 mm, and about 3 mm to about 6 mm. In some embodiments, the
intermediate portion 335 or target zone can include a weakened area
such that the intermediate portion 335 or target zone can be less
resilient to compression in the weakened area. In some embodiments,
the target zone can have a plurality of engagement struts (not
shown) configured to selectively engage the coupling member 320
when the branch stent 330 (and thus the target zone) is in an
expanded state. In other words, the branch stent 330 can be
delivered to a treatment site (e.g., via a delivery catheter), the
engagement struts can be positioned relative to the coupling member
320, and the plurality of engagement struts can be moved into
engagement with the coupling member 320 (e.g., via expanding an
expandable member 340). The plurality of engagement struts can form
at least a portion of the weakened area of the intermediate portion
335 or target zone. In some embodiments, the plurality of
engagement struts can include three to twelve engagement struts. In
some embodiments, the plurality of engagement struts can include
four to six engagement struts. The engagement struts can define
openings or windows in the engagement portion 332 of the branch
stent 330, each of the openings or windows being disposed between
two engagement struts. Thus, due to the openings or windows between
the engagement struts, the engagement struts can be sufficiently
thin such that the engagement struts can be less resilient to
compression than other portions of the branch stent 330.
[0065] In some embodiments, the intermediate portion 335 or target
zone can include a weakened portion that is less resilient to
compression than other portions of the branch stent 330 due to
being less thick, less wide, of a more elastic material, or shaped
such that the weakened portion is sufficiently compressible. In
some embodiments, some engagement struts of the plurality of
engagement struts can be more rigid than others, such that some of
the engagement struts are less resilient to compression and/or
expansion than other engagement struts. The openings or windows
referred to herein can include pass-through, cut-outs, less rigid
structures (e.g., struts) disposed between more rigid structures
(e.g. more rigid struts), and/or any other suitable weakened area
or structure that an expandable member (e.g., expandable member
340) can expand into or displace relative to other portions of an
engagement portion (e.g., engagement portion 332) of a stent. In
some embodiments, the openings or windows referred to herein can be
covered and an expandable member (e.g., expandable member 340) can
expand into the space defined by, for example, the struts and the
cover. In some embodiments, the openings or windows referred to
herein can be uncovered such that an expandable member (e.g.,
expandable member 340) can expand into the space defined by, for
example, the struts, and can further expand through the openings or
windows and beyond the outer surface of the engagement portion
(e.g., engagement portion 332).
[0066] In some embodiments, the plurality of engagement struts can
have particular shapes such that, during expansion of the branch
stent 330 and/or contraction of the coupling member 320, the
coupling member 320 can align with a particular portion of the
engagement portion 332 of the branch stent 330. Said another way,
the engagement portion 332 can be shaped and/or structured such
that the engagement portion 332 can self-align with the coupling
member 320 when the branch stent 330 transitions from the
contracted configuration to the expanded configuration or when the
coupling member 320 transitions from the expanded configuration to
the contracted configuration. In some embodiments, the engagement
portion 332 can self-align with the coupling member 320 due to the
engagement struts having a weakened portion, a curved portion, a
flexible portion, or some other type of structure or shape that
causes the engagement struts or a particular segment of the
engagement struts to be more susceptible to being contracted or
contracted to a smaller diameter by the coupling member 320 than
another portion of the branch stent 330 or another segment of the
engagement struts. Some example engagement strut shapes are shown
and described below with respect to branch stents 830, 930, 1030,
and 1130 as shown in FIGS. 10A-10C, respectively.
[0067] In some embodiments, the engagement portion 332 can include
a protruding tab (not shown) configured to selectively engage the
coupling member 320. In other words, the protruding tab can be
disposed near the coupling member 320 and moved into engagement
with the coupling member 320 via, for example, the expandable
member 340. In some embodiments, the engagement portion 332 can
include a first protruding tab (not shown) configured to be
disposed proximal to the coupling member 320 and/or a second
protruding tab (not shown) configured to be disposed distal to the
coupling member 320. The first protruding tab and the second
protruding tab can be configured to engage the coupling member
320.
[0068] In some embodiments, the engagement portion 332 can include
a first set of protruding tabs (not shown) configured to be
disposed proximal to the coupling member 320 and/or a second set of
protruding tabs (not shown) configured to be disposed distal to the
coupling member 320. The first set of protruding tabs and the
second set of protruding tabs can be configured to engage the
coupling member 320. For example, each of the protruding tabs in
the first set of protruding tabs can be configured to be aligned
with a corresponding protruding tab in the second set of protruding
tabs. Each of the protruding tabs in the first set of protruding
tabs can be configured to be offset from a corresponding protruding
tab in the second set of protruding tabs. The first set of
protruding tabs and the second set of protruding tabs can each
include at least two protruding tabs, at least three protruding
tabs, at least four protruding tabs, at least five protruding tabs,
at least six protruding tabs, at least seven protruding tabs, at
least eight protruding tabs, at least nine protruding tabs, at
least ten protruding tabs, at least eleven protruding tabs, at
least twelve protruding tabs, between two and twelve protruding
tabs, between three and eight protruding tabs, between four and six
protruding tabs, or any suitable number of protruding tabs. In some
embodiments, each protruding tab of the engagement portion 332 can
have an undeployed state and a deployed state. In the deployed
state, each protruding tab of the engagement portion 332 can
protrude beyond the outer surface of the branch stent 330 by a
distance equal to at least about 20% of the nominal thickness of
the frame of the branch stent 330.
[0069] The expandable member 340 can be or include, for example, a
balloon. The expandable member 340 can be expandable via any
suitable fluid, such as, for example, air or a liquid. The
expandable member 340 can include a first portion 342 and a second
portion 344. The first portion 342 of the expandable member 340 can
be configured to expand the engagement portion 332 of the branch
stent 330. The second portion 344 of the expandable member 340 can
be configured to expand the flexible tail portion 334 of the branch
stent 330. In some embodiments, when the expandable member 340 is
in the expanded configuration, the first portion 342 of the
expandable member 340 can have a larger diameter than the second
portion 344 of the expandable member 340. In some embodiments, the
expandable member 340 can have a stepped outer profile such that
the first portion 342 has a first constant diameter and the second
portion 344 has a second constant diameter, the first portion 342
and the second portion 344 being coupled by a tapered transition
portion. In some embodiments, rather than the expandable member 340
having a stepped outer profile, the first portion 342 can have a
saddle or hourglass shaped outer profile. In other words, the first
portion 342 of the expandable member can include a proximal portion
341, an intermediate portion 345, and a distal portion 343. When in
the expanded configuration, the intermediate portion 345 can have a
diameter less than the diameter of the proximal portion 341 and/or
the distal portion 343.
[0070] In some embodiments, the expandable member 340 can be formed
of a semi-compliant material. In some embodiments, the first
portion 342 of the expandable member 340 can be formed of a
semi-compliant material and the second portion 344 of the
expandable member 340 can be formed of a non-compliant material. In
some embodiments, the first portion 342 of the expandable member
340 can have a first compliance and the second portion 344 of the
expandable member 340 can have a second compliance less than the
first compliance. In some embodiments, the expandable member 340
(e.g., both the first portion 342 and the second portion 344) has a
compliance of less than about 10%. The compliance of the expandable
member 340 can be determined using the following equation.
Compliance ( % ) = ( .0. High ATM - .0. Low ATM ) .0. Low ATM
.times. 100 % ##EQU00001##
[0071] In some embodiments, the expandable member 340 is initially
extruded as a balloon with a constant wall thickness and a
substantially constant diameter. The first portion 342 can be
formed such that the first portion 342 has a reduced wall thickness
compared to the second portion 342. When the expandable member 340
is inflated, the first portion 342 having reduced wall thickness
will expand before and/or more quickly than the second portion 344.
The first portion 342 can expand such that the first portion 342
engages with engagement struts of the engagement portion 332 of the
branch stent 330. As the first portion 342 continues to expand, the
first portion 342 can expand into a weakened area (e.g., the
openings or windows) in the engagement portion 332 of the branch
stent 330, securing the expandable member 340 relative to the
branch stent 330. Thus, the branch stent 330 can be prevented from
separating from the expandable member 340 during the expansion of
the expandable member 340.
[0072] In some embodiments, a portion of the first portion 342 can
expand into the weakened area (e.g., openings or windows) in the
engagement portion 332 before the engagement portion 332 begins to
expand under the expanding force of the expandable member 340. In
some embodiments, a portion of the first portion 342 distal of a
proximal end portion of the expandable member 340 can expand to an
increased outer diameter compared to the outer diameter of the
proximal end portion of the expandable member 340 prior to the
expansion of, for example, a band or ring of closed cells in the
proximal portion 331 of the branch stent 330. In some embodiments,
prior to or at the point of the engagement portion 332 of the
branch stent 330 first expanding into a contact relationship with
the coupling member 320, the expandable member 340 and the branch
stent 330 can have a larger diameter in, for example, the
intermediate portions 345 and 335 of the expandable member 340 and
the branch stent 330, respectively, or the target zone of the
branch stent 330 than the diameter of the proximal portions 341 and
331 of the expandable member 340 and the branch stent 330,
respectively and/or distal portions 343 and 333 of the expandable
member 340 and the branch stent 330, respectively.
[0073] In some embodiments, the first portion 342 and the second
portion 344 of the expandable member 340 can be in fluidic
communication with each other and fluidically coupled to a single
fluid supply mechanism, such as a tube. In some embodiments, the
expandable member 340 can include a radiopaque marker or band (not
shown). The radiopaque marker or band can be positioned near or
within the intermediate portion 345 of the first portion 342 of the
expandable member 340 such that, when the branch stent 330 is
aligned with the expandable member 340 such that the intermediate
portion 335 of the branch stent 330 is aligned with the
intermediate portion 345 of the expandable member 340, the target
zone of the branch stent 330 can be aligned with the coupling
member 320 using, for example, radiographic imaging.
[0074] In some embodiments, the branch stent 330 can include a
stent cover (not shown). In some embodiments, the stent cover can
full cover the entire outer surface of the branch stent 330. In
some embodiments, the stent cover can cover only the tail portion
334 of the branch stent 330. In some embodiments, the stent cover
can cover the tail portion 334 and at least a portion of a
transition portion and/or engagement portion 332 of the branch
stent 330. The stent cover can be formed of any suitable material,
such as, for example, expanded polytetrafluoroethylene (ePTFE) or
espun poly(tetrafluoroethylene) (espun PTFE). The cover can have
the same or similar strain potential as described in International
Application No. PCT/US2017/044822, filed Aug. 1, 2017, entitled
"Systems, Devices, and Methods for Coupling a Prosthetic Implant to
a Fenestrated Body", Which is hereby incorporated by reference in
its entirety.
[0075] For example, as shown in FIG. 5A, the expandable member 340
can be disposed within a lumen of the branch stent 330. The branch
stent 330 and the expandable member 340 can then be inserted into
the fenestration 365 of the fenestrated body 360 such that the
coupling member 320 surrounds the branch stent 330 and the
expandable member 340. More specifically, the branch stent 330 and
the expandable member 340 can be disposed within the fenestration
365 such that a target zone (e.g., the intermediate portion 335) of
the branch stent 330 is aligned with the coupling member 320.
[0076] As shown in FIG. 5B, the expandable member 340 can then be
expanded (e.g., inflated) such that the expandable member 340
applies an expanding force against the inner wall of the branch
stent 330. The expanding force can cause the branch stent 330 to
expand in diameter and engage with the coupling member 320. The
expandable member 340 can be further expanded such that the
expanding force of the expandable member 340 causes the branch
stent 330 to apply an expanding force to the coupling member 320
such that the coupling member 320 expands from a first diameter D1
(shown in FIG. 5A) to a second diameter 172 (shown in FIG. 5B). In
some embodiments, the second diameter D2 can be up to three times
the first diameter D1. In some embodiments, the expansion of the
expandable member 340 can cause the proximal portion 331 and the
distal portion 333 of the branch stent 330 to further expand on the
proximal side and the distal side, respectively, of the coupling
member 320. The lack of resistance (compared to the resistance to
the expanding force of the expandable member 340 in combination
with the branch stent 330 applied by the coupling member 320)
allows the branch stent 330 to expand to a saddle-like shape with
the proximal portion 341 on the proximal side of the coupling
member 320 and the distal portion 343 on the distal side of the
coupling member 320. In other words, each of the proximal portion
341 and the distal portion 343 can have a larger diameter than the
diameter of the coupling member 320 and the intermediate portion
345 of the expandable member 340 in the configuration shown in FIG.
5B.
[0077] As shown in FIG. 5C, the expandable member 340 can then be
contracted (e.g., deflated) such that the expanding force
previously applied by the expandable member 340 against the branch
stent 330 and the coupling member 320 is removed. As a result, the
coupling member 320 can contract to a third configuration with a
third diameter D3. In some embodiments, the branch stent 330
(including the proximal portion 331, the intermediate portion 335,
and the distal portion 333 can contract due to the removal of the
expanding force applied by the expandable member 340. In some
embodiments, the branch stent 330 can contract due to a contraction
force applied by the coupling member 320 to the intermediate
portion 335 when the coupling member 320 contracts to the third
configuration. In some embodiments, the third diameter D3 can be
greater than the first diameter D1. In some embodiments, the third
diameter D3 can be substantially equal to the first diameter
D1.
[0078] As shown in FIG. 5D, the expandable member 340 can be
removed from within the branch stent 330, leaving the branch stent
330 secured to the fenestrated body 360 via the coupling member
320. In such a configuration, the coupling member 320 and the
branch stent 330 can be coupled such that the branch stent 330 can
pivot about the fenestration 365 of the fenestrated body 360 and
the axial movement of the branch stent 330 relative to the
fenestrated body 360 is limited due to the contraction force
applied by the coupling member 320 on the intermediate portion 335
of the branch stent 330.
[0079] In some embodiments, the first portion 342 of the expandable
member 340 can be configured to have a diameter in the expanded
configuration that is greater than an inside diameter of the
coupling member 320 after the expandable member 340 has been
expanded and contracted (see FIG. 5C). In some embodiments, the
diameter of the expandable member 340 (and thus, the proximal
portion 331 and the distal portion 333 of the branch stent 330) in
the expanded state (see FIG. 5B) can be at least about 0.5 mm
greater than the inside diameter of the coupling member 320 in the
third configuration (see FIG. 5C).
[0080] FIG. 6 is a front view of a radially expandable coupling
member 420. The coupling member 420 can be the same or similar in
structure and/or function to any of the coupling members described
herein. For example, the coupling member 420 can be formed as a
coil having a first end 424 and a second end 426. The first end 424
can be coupled to the second end 426 via any suitable connection
method or mechanism (e.g., via welding) such that the coupling
member 420 forms a ring. The coupling member 420 can be coupled to
a fenestrated body (e.g., the fenestrated body 360) such that the
coupling member 420 is disposed about (e.g., fully or completely
surrounding) a fenestration defined by the fenestrated body (e.g.,
the fenestration 365).
[0081] The coupling member 420 can be coupled to a fenestrated body
via any suitable coupling mechanism. For example, the coupling
member 420 can be stitched to a fenestrated body using, for
example, sutures. In some embodiments, the coupling member 420 can
be coupled to a fenestrated body via polyurethane. In some
embodiments, the coupling member 420 can be coupled to a
fenestrated body via a mechanical coupling, via welding, or via any
apparatus or method described in the '157 application.
[0082] The coupling member 420 can be configured to expand from a
first configuration having a first diameter to a second
configuration having a second diameter in response to the
application of an expanding force, such as an expanding force
applied by any of the expandable members described herein (e.g.,
expandable member 340). After expanding, the coupling member 420
can be configured to contract from the second configuration to a
third configuration having a third diameter upon removal of the
expanding force. In some embodiments, the third diameter can be
substantially equal to the first diameter. In some embodiments, the
third diameter can be greater than the first diameter.
Additionally, the coupling member 420 can be configured to engage
with a branch stent graft, such as any of the branch stents
described herein (e.g., branch stent 330). For example, an
expandable member can be expanded within a branch stent such that
the expandable member applies an expanding force to an inner wall
of the branch stent, causing an outer wall of the branch stent to
contact, engage with, and/or expand the coupling member 420 from
the first configuration to the second configuration. When the
expanding force is removed (e.g., via deflation and/or removal of
the expandable member), the coupling member 420 can contract and
apply a force to the branch stent sufficient to decrease a diameter
of the branch stent.
[0083] FIG. 7 is a perspective view of a radially expandable
coupling member 520. The coupling member 520 can be the same or
similar in structure and/or function to any of the coupling members
described herein. For example, the coupling member 520 can include
a coil 521 having a first end 524 and a second end 526. The first
end 524 can be coupled to the second end 526 via any suitable
connection method or mechanism e.g., via welding) such that the
coupling member 520 forms a ring. The coupling member 520 can be
coupled to a fenestrated body (e.g., the fenestrated body 360) such
that the coupling member 520 is disposed about (e.g., fully or
completely surrounding) a fenestration defined by the fenestrated
body (e.g., the fenestration 365).
[0084] The coupling member 520 can include a shape memory core 522
disposed within the coil 521 (e.g., within a central lumen of the
coil 521). The shape memory core 522 can include a shape memory
material or structure such that the shape memory core 522 can
revert to a predetermined shape (e.g., a circular shape). For
example, the shape memory core 522 can include a shape memory
material such that the coupling member 520 can revert to a circular
shape after being collapsed or compressed for delivery to a
particular vascular location via a delivery sheath. The shape
memory core 522 can also prevent kinking of the coil during the
collapsing, delivery, and expansion of the coil at the desired
vascular location. In some embodiments, the shape memory core 522
can include a shape memory alloy, such as, for example, Nitinol
(i.e., nickel titanium). In some embodiments, the coil 521 in
combination with the shape memory core 522 can have a spring rate
of at least about 0.025 N/mm. In some embodiments, the coil 521
alone (i.e., without the shape memory core 522) can have a spring
rate of at least about 0.025 N/mm.
[0085] FIGS. 8A and 8B are a perspective view of a coil 621 and a
shape memory core 622 of a radially expandable coupling member in
an unassembled configuration, respectively. The coil 621 and the
shape memory core 622 can be the same or similar in structure
and/or function to any of the coils or shape memory cores,
respectively, described herein. For example, the coil 621 has a
first end 624 and a second end 626. The first end 624 can be
coupled to the second end 626 via any suitable connection method or
mechanism (e.g., via welding) such that the coil 621 forms a ring.
The coil 621 can be coupled to a fenestrated body (e.g., the
fenestrated body 360) such that the coil 621 is disposed about
(e.g., fully or completely surrounding) a fenestration defined by
the fenestrated body (e.g., the fenestration 365).
[0086] As shown in FIG. 8B, the shape memory core 622 can be shaped
as a split key ring having a first end 625 and a second end 627.
The shape memory core 622 can be coupled to and/or disposed within
a coupling member such as the coil 621 of FIG. 8A. For example, the
coil 621 can be threaded over the shape memory core 622 (e.g., the
first end 625 can be threaded through a central lumen of the coil
621) until the shape memory core 622 is fully within the coil 621
and the first end 624 and the second end 626 of the coil have been
coupled together. Due to the split key ring shape of the shape
memory core 622, when the coil 621 expands, the shape memory core
622 can also expand and the first end 625 of the shape memory core
622 can separate from the second end 627 of the shape memory core
622. When the coil 621 contracts to a smaller diameter, the shape
memory core 622 can also contract and the first end 625 of the
shape memory core 622 can move closer to the second end 627 of the
shape memory core 622.
[0087] FIG. 9 is a top view of a portion of a branch stent 730 in
an undeformed, initial state, but cut and unrolled into a flat
sheet for ease of illustration. The branch stent 730 can be the
same or similar in structure and/or function to any of the branch
stents described herein, such as branch stent 330. As shown in FIG.
9, the branch stent 730 includes an engagement portion 732, a
transition portion 751, and a flexible tail portion 734. The
engagement portion 732 can include a proximal portion 731, an
intermediate portion 735, and a distal portion 733. Said another
way, the branch stent 730 can have four regions: a first region R1,
a second region R2, a third region R3, and a fourth region R4. The
first region R1 can include the proximal portion 731 of the branch
stent 730, the second region R2 can include the intermediate
portion 735 of the branch stent 730, the third region R3 can
include the distal region 733 and the transition portion 751 of the
branch stent 730, and the fourth region R4 can include the flexible
tail portion 734 of the branch stent.
[0088] The proximal portion 731 (i.e., the first region R1) of the
branch stent 730 can include a band or ring 738. The band 738 can
include a number of closed cells, such as, for example, closed cell
739A and closed cell 739B. Each of the closed cells 739 can have a
diamond shape. The band 738 can be configured and positioned
relative to an expanding member (e.g., a balloon) or coupling
member such that the band 738 can provide increased radial strength
to the proximal end of the branch stent 330 from collapsing or
shifting relative to the expanding member or the coupling
member.
[0089] As shown in FIG. 9, the intermediate portion 735 (i.e., the
second region R2) of the branch stent 730 can include a number of
engagement struts 736, such as, for example, engagement strut 736A
and engagement strut 736B. The engagement struts can be configured
to selectively engage a coupling member (such as coupling member
320) when the branch stent 730 is in an expanded state. Although
the branch stent 730 is shown as including six engagement struts
736, the branch stent 730 can include any suitable number of
engagement struts.
[0090] The engagement struts 736 can partially defined windows or
openings 737 between the engagement struts 736 that can form a
weakened area of the branch stent 730. For example, engagement
strut 736A and engagement strut 736B can form opposite sides of an
opening 737. The openings 737 can be shaped and/or sized such that
an expandable member (e.g., a balloon) can expand into engagement
with the engagement struts 736 and can further expand into the
opening 737 such that the expandable member is secured or anchored
to the branch stent 730. In some embodiments, the engagement struts
736 can be disposed in pairs such each pair is spaced from another
pair by a closed cell from the band 738, creating wider openings
737 between pairs of engagement struts 736.
[0091] Additionally, in some embodiments, the engagement portion
732 can include protruding tabs 750 (also referred to as "locking
tabs"). The protruding tabs 750 can be configured to selectively
engage a coupling member the coupling member 320). For example, the
engagement portion 732 includes a first protruding tab 750A
configured to be disposed proximal to a coupling member and a
second protruding tab 750B configured to be disposed distal to the
coupling member. The first protruding tab 750A and the second
protruding tab 750B can be configured to selectively engage a
coupling member. The first protruding tab 750A can be configured to
align with the second protruding tab 750B on opposite sides of a
coupling member. As shown in FIG. 9, a pair of protruding tabs 750
can be disposed between pairs of engagement struts 736. In some
embodiments, each protruding tab 750 can have an undeployed state
and a deployed state. In the deployed state, each protruding tab
750 can protrude beyond the outer surface of the branch stent 730
by a distance equal to at least about 20% of the nominal thickness
of the frame of the branch stent 730. In some embodiments, as shown
in FIG. 9, a protruding tab 750 can form a portion of a closed cell
739 of the band 738.
[0092] FIGS. 10A-10C are views of various engagement strut shapes
in unexpanded configurations. Specifically, FIG. 10A shows a
portion of a branch stent 830. The branch stent 830 includes
engagement struts 836. The engagement struts 836 have a curved or
semi-circular shape.
[0093] FIG. 10B shows a portion of a branch stent 930. The branch
stent 930 includes engagement struts 936. The engagement struts 936
can have a sinusoidal shape, serpentine shape, or a shape including
three or more curves.
[0094] FIG. 10C shows a portion of a branch stent 1030. The branch
stent 1030 includes engagement struts 1036. The engagement struts
1036 have a straight shape.
[0095] FIG. 11 is a side view of an expandable member 1240 in an
expanded configuration. The expandable member 1240 can be the same
or similar in structure and/or function to any of the expandable
members described herein, such as, for example, the expandable
member 340. The expandable member 1240 can include a balloon 1247.
The balloon 1247 can include a first portion 1242 and a second
portion 1244. As shown in FIG. 11, expandable member 1240 can have
a stepped outer profile such that the first portion 1242 and the
second portion 1244 each have a substantially constant outer
diameter, the first portion 1242 and the second portion 1244 being
coupled by a tapered transition portion 1251.
[0096] The expandable member 1240 can also include an inflation
tube 1249. The inflation tube 1249 can be partially disposed within
the balloon 1247 and can be coupled to a source of inflation fluid
outside of the balloon 1247 such that the balloon 1247 can be
fluidically coupled to the source of inflation fluid. The inflation
tube 1249 can be configured to inflate both the first portion 1242
and the second portion 1244 via delivery of inflation fluid to one
or both of the first portion 1242 and the second portion 1244.
[0097] The first portion 1242 of the expandable member 1240 can be
configured to expand an engagement portion of a branch stent (e.g.,
the branch stent 330). The second portion 1244 of the expandable
member 1240 can be configured to expand a flexible tail portion of
a branch stent. As shown, when the expandable member 1240 is in the
expanded configuration, the first portion 1242 of the expandable
member 1240 can have a larger diameter than the second portion 1244
of the expandable member 1240.
[0098] In some embodiments, balloon 1247 of the expandable member
1240 can be initially formed as a balloon with a two wall
thicknesses. The first portion 1242 can be stretched such that the
first portion 1242 has a reduced wall thickness compared to the
second portion 1242. When the balloon 1247 is inflated, the first
portion 1242 having reduced wall thickness will expand before and
more quickly than the second portion 1244. The first portion 1242
can expand such that the first portion 1242 engages with engagement
struts of an engagement portion of a branch stent (e.g., the branch
stent 330). As the first portion 1242 continues to expand, the
first portion 1242 can expand into openings or windows in the
engagement portion of the branch stent, securing the expandable
member 1240 relative to the branch stent. Thus, the branch stent
can be prevented from separating from the expandable member 1240
during the expansion of the expandable member 1240.
[0099] In some embodiments, the expandable member 1240 can include
a radiopaque marker or band 1248. The radiopaque marker or band
1248 can be positioned within the first portion 1242 of the
expandable member 1240 such that, when a branch stent is aligned
with the expandable member 1240 such that an engagement portion of
the branch stent is aligned with the first portion 1242 of the
expandable member 1240, a target zone of the branch stent can be
aligned with a coupling member (such as, for example coupling
member 320) using, for example, radiographic imaging.
[0100] FIG. 12 is a side view of an expandable member 1340 in an
expanded configuration. The expandable member 1340 can be the same
or similar in structure and/or function to any of the expandable
members described herein, such as, for example, the expandable
member 340. The expandable member 1340 can include a balloon 1347.
The balloon 1347 can include a first portion 1342 and a second
portion 1344. As shown in FIG. 11, the first portion 1342 can have
a saddle or hourglass shaped outer profile. In other words, the
first portion 1342 of the expandable member can include a proximal
portion 1341, an intermediate portion 1345, and a distal portion
1343. When in the expanded configuration, the intermediate portion
1345 can have a diameter less than the diameter of the proximal
portion 1341 and/or the distal portion 1343.
[0101] The expandable member 1340 can also include an inflation
tube 1349. The inflation tube 1349 can be partially disposed within
the balloon 1347 and can be coupled to a source of inflation fluid
outside of the balloon 1347 such that the balloon 1347 can be
fluidically coupled to the source of inflation fluid. The inflation
tube 1349 can be configured to inflate both the first portion 1342
and the second portion 1344 via delivery of inflation fluid to one
or both of the first portion 1342 and the second portion 1344.
[0102] The first portion 1342 of the expandable member 1340 can be
configured to expand an engagement portion of a branch stent (e.g.,
the branch stent 330). The second portion 1344 of the expandable
member 1340 can be configured to expand a flexible tail portion of
a branch stent. As shown, when the expandable member 1340 is in the
expanded configuration, the first portion 1342 of the expandable
member 1340 can have a larger diameter than the second portion 1344
of the expandable member 1340.
[0103] FIG. 13 is a flow chart showing a method 1400 of deploying a
branch stent using any of the assemblies or devices described
herein. At 1402, a branch stent can be disposed within a
fenestration of a tubular graft such that an engagement portion of
the branch stent is aligned with a coupling member disposed about
the fenestration. The coupling member can be expandable from a
first configuration to a second configuration. At 1404, the branch
stent can be radially expanded via an expandable member disposed
within the branch stent such that the engagement portion of the
branch stent applies an expanding force to the coupling member. The
expanding force can be operable to expand the coupling member from
the first configuration to the second configuration. At 1406, the
expanding force can be removed and the coupling member can be
allowed to contract to a third configuration. The coupling member
can be operable to apply a contracting force to the branch stent as
the branch stent transitions from the second configuration to the
third configuration.
[0104] While various embodiments of the system, methods and devices
have been described above, it should be understood that they have
been presented by way of example only, and not limitation. For
example, the system, methods, and/or devices described herein can
be used with respect to any suitable branch vessel, such as, for
example, a juxta-renal, a supra-renal, a para-renal, a thoracic, an
iliac, or any other branch vessel. Where methods and steps
described above indicate certain events occurring in certain order,
those of ordinary skill in the art having the benefit of this
disclosure would recognize that the ordering of certain steps may
be modified and such modifications are in accordance with the
variations of the invention. Additionally, certain of the steps may
be performed concurrently in a parallel process when possible, as
well as performed sequentially as described above. The embodiments
have been particularly shown and described, but it will be
understood that various changes in form and details may be
made.
[0105] For example, although various embodiments have been
described as having particular features and/or combinations of
components, other embodiments are possible having any combination
or sub-combination of any features and/or components from any of
the embodiments described herein. In addition, the specific
configurations of the various components can also be varied. For
example, the size and specific shape of the various components can
be different than the embodiments shown, while still providing the
functions as described herein.
* * * * *